Heat a large, heavy-bottomed pot over medium heat. Once the pot is hot, add the oil and swirl it around.
Add the onions, celery and fennel, and stir. Cook, stirring often, until vegetables are soft and slightly translucent, about 6-7 minutes. If the vegetables are browning too fast, lower the heat.
Add the leeks and continue to cook until they turn bright green and soft, about 3 minutes.
Add the garlic and red pepper flakes, if using. Stir until fragrant, about 30 seconds.
Add the potatoes and white beans. Season liberally with salt and pepper, and stir.
Add the vegetable stock to the pot and stir to combine. Place a lid on top of the pot and bring everything to a boil. Once boiling, set the lid aside slightly so that steam can escape. Lower the heat to a simmer. Cook until potatoes are just starting to get tender, about 12 minutes.
Add the pasta, green beans, and asparagus. Bring to a boil again and then simmer until pasta is tender, about 12 minutes. If the soup is getting a little too thick for your liking at this point, add more stock.
Once pasta is tender, stir in the vegan pesto, parsley, and lemon juice until everything is thoroughly mixed. Taste the soup to check for seasoning and adjust if necessary (more salt, pepper, lemon etc). I like to dollop a little bit of extra pesto on top of individual bowls. Enjoy straight away.
Recipe Notes
Premade pesto from the store certainly makes this soup a lot easier to throw together. I like the vegan basil pesto from Sunflower Kitchen and use it often. My pesto recipe is linked in the ingredients list if you want to go the homemade route.
I used whole grain elbow macaroni for my pasta in these photos.
I used flat, green romano beans as my green beans in the photos. Once they’re sliced up, the cooking time is the same as regular green beans.
Hearty and satisfying with an herbaceous pesto broth, this vegan spring green minestrone will satisfy any type of eater. Ready in 1 hour.